Can you pre-install apps on an OEM install

I'm trying to help a friend fix a low power system and they want steam on their system. I don't really want them to need to install steam themselves so i was wondering if there was a way to pre-install steam on Zorin OS lite

Unfortunately, Steam is not pre-installed on Zorin OS Lite.

https://launchpad.net/~cubic-wizard/+archive/ubuntu/release

Cubic can be used to create a custom .iso of your build of any Ubuntu-Based distro.
Using your chosen distro as a base, set things up with the installed software and configurations just as you want, then create an .iso using Cubic.
Burn that .iso using Ventoy or another etcher to install on another system.

Steam is easily installed with one command:

sudo apt install steam